In electrical lamps, particularly in high intensity discharge (HID) lamps, reliable connection of housing parts to electrical mass or ground is desirable, both for security reasons and for reduction of electromagnetic interference (EMI). This especially applies for discharge lamps, where the lamp base comprises at least a part of the operating electronics, i.e. a driver circuit for operation of the burner and/or starting apparatus for igniting the arc discharge.
US 2006/0119282 A1 describes a high-pressure discharge lamp having a lamp base with an integrated starting apparatus. An electromagnetic shield is provided, which is connected to the ground reference potential of an operating device. The electromagnetic shield is provided as a metal housing which surrounds the lamp base, and has an aperture for a discharge vessel and for electrical connection of the lamp. The metal housing is made from aluminum or from an aluminum/magnesium alloy, or from a galvanized steel sheet. Inside, a lead frame is provided with electrical components of the starting apparatus, which comprises metallic webs embedded in electrically insulating plastic. A metallic tongue protrudes from the lead frame and out of the interior of the lamp base. In the mounted state, the metallic tongue of the metal web is in electrical and mechanical contact with a wall part of the metal housing. The metallic web, in a similar manner to a leaf spring, bears against the metal housing with a clamping fit.